


Stretch

by spiritsl



Category: Transformers: Robots in Disguise (2015)
Genre: Anal Fingering, Anal Sex, First Time, M/M, Sticky Sexual Interfacing
Language: English
Status: Completed
Published: 2018-03-28
Updated: 2018-03-28
Packaged: 2019-04-14 04:34:54
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,172
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14128182
Author URL: https://archiveofourown.org/users/spiritsl/pseuds/spiritsl
Summary: Bumblebee and Grimlock try something a little new, and a little coaching goes a long way.





	Stretch

**Author's Note:**

> A looong overdue request from my Tumblr operationrobutts that is finally finished! Would you believe I wrote this in two days? Crazy what motivation does for a person. If you like what you see request something! I'm finally organized enough to start writing again!

Bee shivered as the cold lube was poured between his presented aft cheeks, his hands grabbing fistfuls of the bed as the goo dripped down over his exposed afthole and eventually down to his valve. Grim let out a deep and growling chuckle from behind him, thick fingers spreading his aft cheeks to better see the smaller bots privates as they were engulfed in lube. Despite the fact that his partner had been down there many times before, Bee couldn't help but blush at the intense eyeing up. Grimlock may have been very familiar with his valve, but his afthole had never been the center of attention for any bot that had come or gone down there... Until now...

"Grim, you're not here just to look at it..." Bee said, lifting his upper aft so he didn't feel quite as presented. Grim playfully squeezed his ample cheeks in response.

"Hehe, feelin a lil shy, honeybee?" Grim teased, keeping both large cheeks cupped in his sizable hands.

"No, it's just... Not used to having _t_ _hat_  part of me stared at..." Bee mumbled, trying to make his behind less obvious but unintentionally giving it an enticing wiggle.

Grim chuckled at the movement. "Can't help it. It's too cute."

Bee froze in his spot before throwing an almost offended glance back over his shoulder.

"Cute?! How's it cute?"

Rubbing his hand along the curve of his mates thighs, Grimlock gave a smirk and let the question sit before answering at his own confident pace.

"It's all little and tight, you can tell nobody's been in before... Like it's been waiting for me..."

Blushing and burying his face in the covers, Bumblebee tried to ignore the image Grims words was bringing up. It wasn't too pleasant to imagine it was _that_  easy to tell he was a virgin. Or at least, an aft virgin. It probably was obvious though, considering he'd never even been brave enough to stick anything up or around there. But did that really make it so tight you could see it? For his sake, he hoped not...

"Can we just start now?" He asked, hoping not to lose his nerve with all the over thinking. Grimlock let out a deep and satisfied rumble, leaning forward so that his codpiece bumped Bees thigh and he was able to lay a kiss between his doorwings.

"Whatever you want, honeybee. Just say so if you want to stop. First, I gotta get rub it in, get you nice and prepped."

Bumblebee held a pillow beneath his chin and hugged it tight in anticipation. Of what, he wasn't sure. Pain? Why would it hurt? Grim wasn't going in yet, he was just getting things ready. He'd done this before with his valve countless times. Getting the lube ready, rubbing it in, preparing himself for the stretch. Why was he so nervous? This wasn't that different. He was just taking it up a different hole, and there was no reason to believe-

"Ahhhh..."

His train of thought came to an abrupt halt as a familiar digit dipped into his valve, rubbing itself between the folds to gather natural and artificial lube with practiced ease. Gliding over the slick lips, Grimlock took his time to show the area some love, moving his thumb over the small but eager clit that was rising to the occasion. Bee made sure to show his appreciation, even if he didn't know it. His hips pushed back into the touch with small arches, his body naturally angling itself to try and push the dinobot inside. Grimlock smirked at the enthusiasm, taking it as a  wordless compliment. But he wasn't here for this hole...

Making sure his finger was nice and wet, he started trailing upward, going past the tender folds and between the presented cheeks. Bee stiffened, but didn't protest. He took that as a cue to continue, but take it easy. Using his other hand, he massaged his digits into the presented aft with a kind of reverence, loving how the cheeks seemed to swallow whatever was pressed into them. Fit and slim as Bee was, he had a very cushy behind, something the dinobot had been sure to praise every time he had the opportunity. Big bots liked big behinds, as the saying went... Gauging Bee's readiness to be increasing, he moved his slick digits in for the hole at the center of the attention, only to stop when Bee let out a small sound.

"Shhhh, easy Bee... I'll take it nice and slow..." He soothed, reeling himself in. He'd been dreaming of getting inside Bee in every way for as long as they'd been together, but it would never happen at the expense of his partners comfort. He just needed to make sure Bee was relaxed. Which, considering the smaller bots tendency to anxiety, was no small feat.

"It's ok. I'm ok." Bee whispered, sounding like he believed himself only marginally more than Grimlock did.

 _Time to turn on the charm..._ Grimlock mused, dropping a low rumble from his chest as he leaned over Bee once more. He brought his face between the bots doorwings and settled a few gentle kisses there, stimulating the sensitive metal just enough to make Bee shudder and relax. Keeping his voice low, he whispered with the tone he knew drove Bee crazy.

"Want me to show you how it can feel good?"

Bee quivered at the sexy purr, his hips automatically giving a weak thrust of arousal. That tone always promised pleasure. Enough to overcome any doubts he could ever have. Unable to speak, he just nodded furiously.

Grimlock took the cue. Moving back down, he went in at a carefully chosen speed, taking a dripping finger straight to the edge of the presented booty hole. Holding back a toothy grin, he started swirling his digit around the puckered edges, applying pressure rythmically and skillfully and holding his vents for the response it would ellicit.

"Oh..."

The soft little sigh made his spark soar. It was exactly what he'd wanted to hear, and all he needed to continue.

The strange feeling the touches gave him was something he lacked the words to describe. It was good, and definitely a very sexual kind of pleasure, but it was very different than the kind his valve gave him. It was new, and foreign, and a little scary... But oh so delicious. Giving a lopsided grin into his pillow, he started tentatively moving his hips with the swirling finger.

"Good?" Grim asked from behind, trying to hide how much he wanted to plunge his finger into the warmth he could feel radiating through the lube.

"Good..." Bee purred in reply, a daring urge rising up from deep in his belly. If this felt good, what did the real deal feel like? Was he even more sensitive on the inside? What could those big fingers do inside of him? Without even realizing it, he started pushing back more insistently, taking so little time to advance that he took his lover by surprise

"Bee?"

All the autobot could think to say was a single word.

"More..."

Grimlock needed nothing more. It was almost impossible to keep the joy off his face as he started swirling a finger downward into the open hole, slowly circling it around to ease his way in without causing any discomfort. To his amazement, the puckered edges spread without resistance, welcoming him into the tight heat like a long lost attachment.

 _Wow..._  The dinobot mused, watching himself disappear halfway to the first knuckle. Bee may have been tight, but his behind was stretching like it was made for this. The thought of what that implied for him sent a throb beneath his codpiece.

 _Wow..._ Bee thought to himself, optics lidding and going askew. The feeling was so new, and strange, and alien, and yet he wanted so much more. He could feel Grimlock sliding deeper and stretching him as his finger descended where nothing had ever been before. And he _liked_  it. The pressure that he'd always heard was so painful felt good, like it was turning on sensory nodes that had been long neglected and were rejoicing at being discovered at last. And it was only growing as Grim went deeper, his first knuckle finally disappearing and his pace quickening to slip the second inside in half the time. He halfway wondered if there'd be a limit-

"Oh, ahhh..."

Grimlock swiped his glossa across his lips when Bee moaned in perfect sync to his fingertip hitting a bump. Years of experience told him he'd finally hit the gold he was looking for. Like an artist at an easel, he slid his finger back into the soft protrusion that had blocked his way, running impossibly tiny circles over it's fleshy edges.

"Hehe, didn't think I'd be hitting that so early..." He teased, savoring each and every whimper that came from Bees overwhelmed vocalizer.

"What is that?" Bumblebee moaned between gasps of delight, clawing at the bedsheets as Grimlock prodded the spot with a little more passion.

"Know how you've got a sweet spot in your valve? There's another one back here." Grimlock explained, punctuating his point by pressing down on the soft bundle. To his delight, he found that it had far more depth than he initially thought. "And it feels like you've got a big one..."

Bumblebee responded only with a gasp and a full body shudder before he could manage words once more. "Please keep going..."

"Might be easier if I could use more fingers-"

"Please...!" Bumblebee begged, desperate for more of what he was feeling. Grimlock did as he was told. In moments, Bee felt the stretch of another finger sliding in beside the first, doubling his previous width. The sensory nodes that had previously just been awakened sprung to life with impressive vigor, sending bursts of pleasure along his backside that resonated deeply within his valve and sheathed spike. Grinding his hips backwards, he blindly searched for the best way to get the stimulation he so craved. The wonderful feelings we're stirring something deep in his valve that he immediately recognized as the beginning of an overload. But it was different from any he'd ever had. It was deep, primitive, pressure based, and almost centered in his aft, and he wanted it _now_. No longer satisfied with what two fingers could provide, he pushed them in deeper and cried out.

"More!"

Happy as he was to hear it, Grimlock couldn't help but be a little amazed. He'd never met a bot so desperate and willing to take anything up the aft so soon after starting it. Willing to comply, he popped in a third finger, marveling at how the bots opening stretched to accommodate him like it was nothing. The sight was anything but unpleasant, and made him realize he was very much being neglected at the moment... Not that he wasn't happy to service Bee first and above himself, but blue balls on a dinobot could be... explosive.

Clearing his vents, he tried to voice his concerns with a subtle request. "So, you want the real thing yet, or...?"

"Oh... Ohhh... Oh... Ohh!"

Bumblebee only continued riding his fingers with enthusiasm, grinding his hips so as to best get pressure on his sweet spot. The autobot that had been an anal virgin mere minutes before was now jerking himself off on an impossibly thick pair of dinobot fingers, his afthole stretching like he was built to take the penetration.

Grimlock bit his lip and strained to keep himself sheathed at the site. All his mind would let him think about was imagining that sweet, glistening hole spreading wide and swallowing his spike in one big gulp. And how amazing Bee would look swirling his aft around his length with the same sounds and enthusiasm he was showing off now. Or how incredible it would feel to leave this ever increasing load deep between those two fat cheeks... None of which would happen if he had to keep watching Bee like this and he inevitably lost control all over Bees presented thighs...

"D-don't stop... Grim...!" Bumblebee begged, starting to sweat as he thrusted himself over the fingers inside of him. He could feel the building pleasure deep inside of him, growing and threatening to reach it's peak. His valve was weeping fluid down his quaking thighs, and his optics were almost tearing up as he neared his finish. It was going to be amazing, Earth shattering, world changing, and he was so _close_. "Keep going... I'm gonna... I'm gonna... I'm...!"

Grimlock couldn't be a spectator anymore. He had to be a part of the grand finale.

With a wet sound, he slipped his fingers out in one pull, leaving a trail of lube that broke only after a considerable distance. The sound was immediately followed by a betrayed whimper as Bee found himself suddenly and inexplicably empty and gaping. His overload stopped cold in his tracks, leaving him stumbling just a few painful steps from the edge that he'd been so close to going over. Shaking and almost in tears, he looked back with an expression of utter betrayal.

"Grim!"

Wasting not a moment, Grimlock freed his aching spike, pulling forth it's throbbing length to help show his intentions. Giving the ribbed edges a comforting stroke, he held the gaping hole before him open with a single thumb.

"The real thing could do a way better job."

Bee went absolutely blank faced in realization. Not needing, or perhaps bit being capable of words, he dropped his front down and threw a hand back to pull his hole open as wide as he could in welcoming. The sight made Grimlocks optics dilate in feral excitement, his teeth baring in a victorious grin as he aimed and moved forward in a single, solid thrust.

"Oooaaahhh!"

Bumblebee arched and cried out as the thickest spike he'd ever known slid right inside the tightest hole on his body. His cheeks visibly spread as his insides stretched to accommodate the dinobot in all his glory, the sensory nodes lining the passageway singing out in jubilation as they were stimulated in ways their owner had never imagined.

Bee let his glossa hang out as he took the spike to the hilt, savoring the impossible fullness it made him feel. Corny as it was, he couldn't help but cry out a compliment.

"Grimlock! It's so... so... _Big_!"

The praise sent the dinobot into his element. Grabbing the thick hips at his mercy, he started to thrust, taking his sweet time to pull out for the first time as relishing in how warm and hot and wet his partner was around him. In no time, he was in a rythm, moving back and forth and smacking his hips into the smaller bot with every thrust. It didn't hurt that his ribs managed to rub right by the sweet spot inside Bee with each and every thrust, drawing a moan from the smaller bot every time he moved. The pleasure began mounting in no time, making both bots sweat and shake as their bodies began to build to a synchronized conclusion.

For his part, Bumblebee only had enough sense left to apologise for the swiftness of his release. "Oh, I'm sorry! I'm so, so close!"

Grimlock wouldn't have cared even if he could have heard him. He was already building to a fast and ground shaking conclusion himself. The transfluid was building deep inside of him, preparing to coat his partners inside with a hot and wet burst of satisfaction. Bumblebee was the same, his valve goinh tight and absolutely weeping as he prepped for the burst of an intense overload. His belly was warming as the pleasure spread across his body, stretching out in small tendrils that prepared to pop with ecstasy when the conclusion came.

One last, rough, particularly askew thrust from Grimlock gave Bees G spot the final hammering it needed to push him over the edge. Stars burst across his optics as his lower body squeezed down tight in one massive, throbbing synchronized chorus that sent a symphony of ecstasy all through his neural network. He cried out without hesitation and tore the bedsheets below him as he squeezed Grimlock for all he was worth, his afthole clamping like a vise to keep his mate sheathed. The pleasure was so great that his valve squirted from the force of the pleasure, sending hot lubricant spraying backwards and across his mates exposed ball bearings.

Grimlock came completely undone as the smaller mech orgasmed all around him, hot fluids splashing forth and across his lower section in spurts. Letting out a full, unrestrained, dinobot roar, he plunged in as deep as he could and proceeded to unleash. Wave upon wave of pleasure crashed over the dinobot as he gushed inside the tight hole of Bees behind. In no time the autobot was filled and the excess was splurging backwards to cover his aft and dribble down his thighs. For his part, Grimlock did everything he could to make sure every last precious drop made its way inside, marking his territory like only a dinobot could until the last waves of his release faded away.

All that could be heard in the bedroom was the hard and hot ventilation's of two very exhausted, very satisfied mechs trying not to collapse on one another. Using the last bit of sense he had, Grimlock slowly pulled them both down to lie across the bed, staying sheathed inside his mate the entire time. It was with some regret that he pulled out and slipped his spike free of the tight, drenched afthole, coming out with a wet * _plop_ * and a small sound of surprise from Bee. The smaller mech literally felt himself become empty afterwards, as well as very aware of just how much he'd been stretched.

"Primus, Honeybee..." Grimlock purred between pants, rubbing his sweat soaked forehead over Bees back. "We gotta do that again..."

"If my ass ever goes back to normal." Bee joked, reaching back and tenderly feeling the soaked and stretched entrance. "I'll be feeling this tomorrow..."

"It'll go back to normal. Remember the first time I got in your valve? All it took was a lil time."

Bee tried to hide a cringe as he remembered how sore he'd been the morning after their first. It had been worth it, of course, but every bot with working optics had taken notice of his limp...

"Sides, now that you're all adjusted, we can have all kind of fun. I learned a lotta tricks with other dinobots."

"Can we just do the "cuddling" trick for now? And maybe the "showering" one later?" Bee asked, suddenly aware of how messy and tired he was. And how amazing the dinobots arms felt after a good frag... Grimlock purred happily, nuzzling up to the smaller mech and gingerly cradling him in his huge embrace.

"I think I can make that happen..."


End file.
